Methods and devices of cleaning subsea structures

ABSTRACT

A tool for cleaning subsea structures, the tool comprising a frame comprising a stationary frame portion; and a rotating frame portion rotationally connected to the stationary frame portion; and at least one cleaning device attached to the rotating frame portion.

FIELD OF THE INVENTION

This application is related to an offshore structure cleaning system.

BACKGROUND OF THE INVENTION

Co-Pending Patent Application Publication WO 2009/094358, filed Jan. 21, 2009 and having attorney docket number TH3355, discloses an offshore structure cleaning system comprising a frame, at least one set of clamps supported by the frame, a cleaning mechanism on an interior of the set of clamps, the cleaning mechanism adapted to clean an offshore structure. Co-Pending Patent Application WO 2009/094358 is herein incorporated by reference in its entirety.

Co-Pending PCT Patent Application number PCT/US2009/060945, filed Oct. 16, 2009 and having attorney docket number TH3513, discloses a tool for cleaning sub sea structures, the tool comprising a frame, and at least one ultrasonic transmitter attached to the frame. Co-Pending Application number PCT/US2009/060945 is herein incorporated by reference in its entirety.

Co-Pending PCT Patent Application number PCT/US2009/060946, filed Oct. 16, 2009 and having attorney docket number TH3592, discloses a tool comprising a frame, and at least one cleaning device attached to the frame. Co-Pending Application number PCT/US2009/060946 is herein incorporated by reference in its entirety.

SUMMARY OF THE INVENTION

One aspect of the invention provides a tool for cleaning sub sea structures, the tool comprising a frame comprising a stationary frame portion; and a rotating frame portion rotationally connected to the stationary frame portion; and at least one cleaning device attached to the rotating frame portion.

Another aspect of the invention provides a method of remotely cleaning a sub sea structure, the method comprising positioning a tool adjacent to the sub sea structure, wherein the tool comprises a stationary portion and a rotating portion comprising at least one cleaning device; moving the tool to position the tool around the sub sea structure; closing the tool to a closed configuration to close the tool around the sub sea structure, wherein the tool covers from about 10% to about 100% of a circumference of the sub sea structure; holding the stationary portion and moving the stationary portion along a length of the sub sea structure, rotating the rotating portion rotates about the circumference of the sub sea structure; and cleaning at least a portion of the sub sea structure.

Advantages of the invention may include one or more of the following:

apparatus and methods for cleaning offshore structures and devices by rotating around the structures;

apparatus and methods for cleaning helical offshore structures;

improved apparatus and methods for cleaning offshore structures and devices; and

apparatus and methods for cleaning offshore structures and devices that do not suffer from the disadvantages of the prior art.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates an example embodiment of a sub sea system.

FIG. 2 is a cross-sectional front view illustrating an embodiment of a cleaning device around a tubular structure.

FIG. 3 is a cross-sectional top view of an embodiment of a cleaning device around a tubular structure taken along section line 3-3 in FIG. 2.

FIG. 4 is a cross-sectional front view illustrating an embodiment of a cleaning device having an alternate embodiment of a rotational connector used to connect a drum to an arm.

FIG. 5 is a front view illustrating an embodiment of a cleaning device including a drum optionally having a plurality of drum hinges or other pivot joints.

FIG. 6 is a partial top view of an embodiment of a cleaning device having hydraulic arms and a hydraulic system to open and close the cleaning device.

FIG. 7 illustrates an embodiment of a remotely operated vehicle manipulating a cleaning device in a sub sea system.

DETAILED DESCRIPTION

FIG. 1 illustrates an example embodiment of sub sea system 100. The sub sea system includes surface structure 101 near a water surface. The surface structure is connected to subsurface structure 104 adjacent to seafloor 105 by a tubular structure 102. In various embodiments, the tubular structure may be a riser, a tendon, an umbilical, or other generally cylindrical tubular structures used in sub sea systems. In the illustration, the tubular structure extends all the way to the seafloor, but in other implementations the tubular structure may not extend all the way to the seafloor.

The sea has current 106, which may cause vortex-induced vibration (VIV) of tubular structure 102. To counter such VIV, one or more VIV suppression devices or structures may be installed along a length of tubular structure 102. In the illustration, helical strakes 108 are affixed or attached to or otherwise installed along a length of the tubular structure to help suppress VIV. Other types of VIV suppression devices or structures, such as, for example, fairings, shrouds, wake splitters, or other VIV suppression devices or structures known in the arts, may be used in place of, or in addition to, helical strakes 108.

Over time, the marine environment may cause marine growth (e.g., slime, seaweed, algae, barnacles, and other plants and animals) to occur on sub sea components, such as, for example, tubular structure 102 and helical strakes 108. This marine growth may tend to inhibit the VIV suppression performance of the helical strakes. For example, excess marine growth may tend to effectively shorten the radial heights of the helical strakes. It may therefore be advantageous to clean at least some of the components or structures of the sub sea system in order to help maintain the ability to effectively suppress VIV.

Various techniques for cleaning sub sea structures are disclosed in U.S. Patent Application No. 61/106,832, filed on Oct. 20, 2008, by Allen et al. Still other techniques for cleaning sub sea structures are disclosed in U.S. Patent Application No. 61/106,802, filed on Oct. 20, 2008, by Allen et al. These applications are presently assigned to the same assignee as the instant application, and are incorporated herein by reference in their entirety.

New and different devices and methods for cleaning sub sea structures may offer certain advantages. In particular, new and different devices and methods well suited for cleaning tubular structures having strakes, or other structures that wind, twist, or spire around the tubular structure, or in which cleaning the structure would benefit from rotation of one or more components around the tubular structure, may offer certain advantages.

FIG. 2:

FIG. 2 is a front, cross-sectional view illustrating an embodiment of cleaning device 210 around tubular structure 202. In one or more embodiments, the tubular structure may have strakes, or other structures or devices that wind, twist, or turn about the tubular structure (not shown in this view).

Cleaning device 210 has upper pair of arms or other sections 212. Likewise, the cleaning device has lower pair of arms or other sections 214. Alternatively, the cleaning device may have only one of either of these pairs of arms.

Upper pair of arms 212 includes, as viewed, upper left arm section 216 and upper right arm section 218. Likewise, lower pair of arms 214 includes, as viewed, lower left arm section 220 and lower right arm section 222. In one or more embodiments, each of the arms of the upper and lower section pairs is approximately hemi-circular in shape, such as, for example, shaped like half a circle.

The upper left and right arms are connected together by upper hinge or other pivot joint 224. Likewise, the lower left and right arms are connected together by lower hinge or other pivot joint 226. In this cross-sectional view, hinges or other pivot joints 224 and 226 appear in dashed lines indicative a location on the backside of cleaning device 210 as viewed.

Cleaning device 210 also includes drum 230. Drum 230 is to be interpreted broadly herein as a generally cylindrical hollow structure or part capable of accommodating a tubular structure. In one or more embodiments, drum 230 may have a body structure including a number of openings therein to help to allow material removed from the tubular structure and/or strakes or other structures attached to the tubular structure to exit the drum. For example, the drum may have perforations, a truss-like structure, or a frame-like structure. The drum may also have an open top and/or bottom to allow material to exit.

As viewed, drum 230 includes left section 232 and right section 234. In one or more embodiments, the drum left and right sections are each approximately hemi-cylindrical in shape, for example, approximately half a cylinder. Left section 232 and right section 234 are connected together by drum hinge 236, shown in dashed lines indicating its location on the back side of cleaning device 210 as viewed. In the illustration, the drum appears tall. In practice, the height of the drum often may range from several inches to several feet.

In the illustration, drum hinge 236 is vertically aligned with upper hinge 224 and lower hinge 226. As shown, in one or more embodiments, cleaning device 210 may optionally have one or more fiducial or alignment marks or structures 238, 239 or an ROV sight guide. For example, the drum may have mark or fiducial 239 that, in this embodiment, is in vertical alignment with mark or fiducial 238 on upper arm section 216 when drum hinge 236 is in precise vertical alignment with hinge 224 of upper arm section 216. Fiducial 238 and fiducial 239 are shown in dashed lines in the cross-sectional view of FIG. 2 to indicate their location, in this embodiment, on a backside of cleaning device 210 as viewed. It will be appreciated that a wide variety of different types of fiducial or alignment marks or structures are suitable, including native features or structures or of the cleaning device itself. Such marks or structures may help to allow a diver or ROV, for example, to know when the hinges are aligned. In one aspect, the cleaning device or an ROV that uses the cleaning device may have an arm or other mechanism to rotate the drum.

When the upper hinge 224 and lower hinge 226 and drum hinge are aligned, cleaning device 210 may be opened and/or closed in a clamshell fashion. In particular, upper hinge 224 may allow the upper pair of arm sections to swing, pivot, or move between an open position and a closed position. Likewise, lower hinge 226 may allow the lower pair of arm sections to swing, pivot, or move between an open position and a closed position. Drum hinge may allow the left and right drum sections to swing, pivot, or move between an open position and a closed position.

In one or more embodiments, cleaning device 210 may optionally have a locking or fastening mechanism to lock or fasten such an aligned configuration in place. One example mechanism is a magnetic latch. Another example mechanism is a hydraulically controlled pin capable of engaging a corresponding hole. Such a locking or fastening mechanism may help to assist with keeping the drum and the arms aligned, for example, while moving the cleaning device from one tubular structure to another. When the drum is ready to be rotated, the mechanism may be controlled so the drum is free to rotate.

In one aspect, either the upper pair of arm sections, the lower pair of arm sections, or both, are used to open and/or close the device. For example, either or both of the pair of arm sections may be controlled by a diver, ROV, or from surface structure 101 (e.g., by a control line from the surface structure). The arm sections may be controlled hydraulically, or otherwise. The arm sections may apply force on the drum sections to cause the drum to open. Likewise, upward and/or downward forces on the arm sections may be used to move cleaning device 210 upward and/or downward along a length of the tubular structure.

The ability to open and close cleaning device 210 allow the cleaning device to be placed around and removed from around the tubular structure. A representative method of placing cleaning device 210 around a tubular structure (e.g., tubular structure 202) may include moving the cleaning device until it is positioned in front of the tubular structure, opening the cleaning device, introducing the tubular structure into the opening in the cleaning device, and closing the cleaning device around the tubular structure. Then the tubular structure may be cleaned with the cleaning device. After cleaning, a method of removing the cleaning device from around the tubular structure may include opening the cleaning device, moving the cleaning device away from the tubular structure until the tubular structure leaves the opening, and then optionally closing the cleaning device.

Once placed around the tubular structure, cleaning device 210 may be used to clean the tubular structure, strakes (or other structures or devices) attached to the tubular structure, or both. Cleaning may include removing marine growth, dirt, debris, rust, or other fouling. As used herein, cleaning does not require any known level or extent of cleaning, and does not require complete removal of all of such materials. Rather, cleaning refers broadly to the actions performed by which at least some of such materials are generally removed.

Cleaning tubular structures having helical strakes offers certain unique challenges. For one thing, the helical strakes spire or twist helically around the tubular structure. Certain cleaning devices would need to be rotated around the tubular structure in order to effectively clean the helical strakes and the portions of the tubular structure between the helical strakes. However, it may tend to be difficult for a diver or ROV to maneuver the rotation of the cleaning device around the tubular structure. Furthermore, in some cases it may be desirable to include one or more lines from a surface structure to the cleaning device, such as, for example, a power line, a control line, a support line, and/or a high pressure cleaning fluid line. However, these lines may tend to twist or tangle around the tubular structure when the cleaning device is rotated around the tubular structure, which in part may tend to restrict or limit further vertical movement of the cleaning device. Accordingly, cleaning devices better adapted at cleaning tubular structures having strakes, or other structures that twist, turn, spire, or rotate around the tubular structure, would tend to offer certain advantages.

Referring again to FIG. 2, in one or more embodiments, drum 230 may be rotationally connected between upper pair of arms 212 and lower pairs of arms 214. In one or more embodiments, drum 230 of cleaning device 210 may be able to rotate (e.g., rotating around tubular structure 202) without either of upper pair of arms 212 or lower pairs of arms 214 rotating (e.g., rotating around the tubular structure). In one or more embodiments, if a remote operated vehicle (ROV) or diver, for example, moves cleaning device 210 up and/or down along a length of the tubular structure, without rotating the upper and lower pairs of arms around the tubular structure, the drum may still be capable of rotating around the tubular structure, such as, for example, if helical strakes attached to the tubular structure exert forces on the drum (e.g., on cleaning brushes or other components inside the drum). Advantageously, this may help to overcome some of the maneuvering challenges previously described and/or may help to reduce twisting of lines around the tubular structure.

In FIG. 2, a particular example of rotational connection is illustrated to rotationally connect drum 230 with upper pair of arms 212. A similar connection is used to connect drum 230 with lower pair of arms 214. In this embodiment, each rotational connection includes a pair of interlocked annular or ring-shaped lips. The connection of drum 230 to upper pair of arms 212 is described below. It is appreciated that, in this embodiment, the connection of drum 230 to lower pair of arms 214 is similar.

Drum 230 includes first annular or ring-shaped lip 240 of the pair. First annular or ring-shaped lip 240 of the drum may project radially outward as a rim, rib, or other annular or ring-shaped lip from the body or perimeter of the drum at the top of the drum. In the embodiment shown in FIG. 2, male member or structure 246 has a length, l₁, that projects vertically downward (as viewed) at or near an end of lip 240.

Upper pair of arms 212 (each of section 216 and section 218) extends a radial length greater than a radial projection of lip 240. Upper pair of arms 212 together form second annular or ring-shaped lip 242 of the pair. As viewed, second annular or ring-shaped lip 242 includes downward projection 2422 from a bottom edge of the arms, radially inward projection 2424, and then upward projection 2426. Collectively, downward projection 2422, inward projection 2424, and upward projection define a U-shaped structure descending from upper pair of arms 212. A length, I₃, of radially inward projection 2424 is at least sufficient to extend beyond a radial width, w, of male member or structure 246. Upward projection 2426 of second annular or ring-shaped lip 242 extends a length, I₄, such that a difference between a length, I₂, of downward projection 2422 and a length, I₄, of upward projection 2426 is greater than a thickness, t₁ of first annular or ring-shaped lip 240, exclusive of male member or structure 246, but the difference is less than length, I₁ of male member or structure 246. In this manner, second annular or ring-shaped lip 242 defines annular or ring-shaped groove 244 beneath the upper pair of arms capable of retaining lip 240 of drum 230 therein with lip 242 of upper pair of arms 212.

Groove 244 of the second annular or ring-shaped lip defines a female opening. As shown, male member or structure 246 of first annular or ring-shaped lip 240 of the drum projects into female annular or ring-shaped groove 244 connecting upper pair of arms 212 to drum 230. The connection of upper pair of arms 212 to drum 230 is such that drum 230 is free to rotate.

In alternate embodiments, a portion of the annular or ring shape of either of the lips may optionally be omitted, as long as there is some part to hold the drum in place when the arms and drum are open so that the drum does not fall out. For example, each of the arms may have such a lip on only about half their perimeter.

If desired, in one or more embodiments, one or more of low friction materials, wheels, bearings, other materials or mechanisms to reduce friction or encourage rotation may optionally be included in the connection between the drum and one or more of the arms. In one or more embodiments, water may be pumped or otherwise forced into the bearings, interfaces, or other connections between the drum and one or more of the arms to help to remove debris, clean these areas, and generally help to reduce friction and/or encourage rotation. For example, water jets or nozzles may be directed at the connections between the drum and one or more arms. In one or more embodiments, the drum may incorporate or have attached thereto one or more low density or buoyant materials having a density less than that of the surrounding water to help to give the drum a lighter weight and help to reduce friction.

This connection, which is illustrative and not limiting, may allow the drum to rotate relative to stationary upper pair of arms. As shown in the illustration, an analogous rotational connection may be used to rotationally connect the drum with lower pair of arms 214. This description is for the device “as viewed”, and the device may be used in a variety of orientations.

FIG. 3:

FIG. 3 is a cross-sectional view of an embodiment of cleaning device 210 around tubular structure 202 taken along section line 3-3 in FIG. 2. Left drum section 232, right drum section 234, drum hinge 236, and drum fiducial or alignment mark or structure 239 are shown. In this view, the upper and lower pairs of arms 212, 214 are not shown.

As shown in this view, tubular structure 202 has strakes 308A, 308B, and 308C. Three strakes are shown, although fewer or more may strakes may optionally be included. Each of the strakes may represent a fin or blade extending radially outward from the tubular structure. The strakes may be helically wrapped around the tubular structure.

As shown, cleaning device 210 may have a size and a shape that is based at least in part on a size and a shape of tubular structure 302 and/or strakes 308A, 308B, and 308C to be cleaned. For example, the size of cleaning device 210, when the cleaning device is closed around the tubular structure and the strakes, may be large enough to accommodate the tubular structure and the strakes, without being so large that cleaning mechanisms inside the cleaning device are placed too far away from the tubular structure and/or the strakes. The drum may encircle and completely surround the tubular structure. As another example, the shape of the inner surface of the cleaning device may be circular or substantially circular in cross-section, when the cleaning device is closed around the tubular structure and the strakes. Alternatively, if the cleaning device is to clean other non-tubular sub sea structures, then it may have other sizes or other shapes.

Referring again to FIG. 3, the cleaning device has at least one type of cleaning mechanism. The illustrated cleaning device has a number of brushes 350, such as, for example, rotating brushes. The brushes have first ends that are fixedly connected with the inner surface of the drum (or ribs 352A, 352B, 352C1/352C2 as discussed further below), and second ends in contact with and/or near the tubular structure and/or the strakes. The rotating brushes may rotate, such as, for example, under hydraulic power, in order to clean the tubular structure and strakes. Force exerted on the brushes by the strakes may help to rotate the drum about the tubular structure as the cleaning device travels along a length of the tubular structure.

However, this type of cleaning mechanism is merely illustrative, and not limiting. Other suitable types of cleaning mechanisms that may be used instead of the brushes, or in addition to the brushes, include, but are not limited to, bristles, scrapers, water jets, ultrasound transducers, and the like, and combinations thereof. Other suitable cleaning devices are disclosed in Patent Application PCT/US2009/031508, U.S. Provisional Patent Application No. 61/106,832, and U.S. Provisional Patent Application No. 61/106,802, discussed above.

Pipes or other channels may be used on or inside of the arm or otherwise configured relative to the cleaning device to provide high pressure water or other fluid to nozzles or water jets to assist with cleaning the structure and/or to assist with removing marine growth and/or other fouling from away from the cleaning device.

In one or more embodiments, when strakes, or like protrusions are present, the drum of the cleaning device may optionally have one or more ribs or other surface extensions 352A, 352B, 352B1/352B2, and 352C. The ribs may extend from an inner surface of the drum of the cleaning device. In one or more embodiments, the ribs may extend a distance from the inner surface of the drum that ranges from about 25% to about 100%, for example from about 50% to about 75% of the distance that the strakes extend from the surface of the tubular structure (or the height of the strakes).

Ribs 352A, 352B1/352B2, and 352C may be spaced around the inner surface of the drum. Channels (spaces without ribs) may exist between adjacent ribs. Each of the channels may be positioned and sized to accommodate a different one of the strakes. The cleaning device may have the same number of ribs as the number of strakes. For example, in the illustration, there are three ribs and three strakes. In this embodiment, rib 352B1 and rib 352B2 combine to form a single effective rib 352B1/352B2 when the cleaning device is in the closed position. The channels between the ribs may be at least as wide as the strakes so that each of the ribs fits between two adjacent strakes without undue interference.

As shown, at least some of the brushes or other cleaning mechanisms may be connected to the ribs. The surfaces of the ribs are extended surfaces that extend closer in proximity to the surface at the outer diameter of the tubular structure between the strakes. Advantageously, this may help to position the brushes or other cleaning mechanisms in closer proximity to the surface at the outer diameter of the tubular structure between the strakes, which may help to facilitate cleaning; and/or the ribs may facilitate the rotation of the drum sections 232, 234 about tubular 202. Without the ribs, the strakes may tend to increase the distance separating the cleaning mechanism from such surfaces. Other approaches, such as, for example, by using longer brushes, are also contemplated.

Ribs 352A, 352B1/352B2, and 352C may extend along at least part of the length of the drum, which in the illustration is into the page. The ribs may be sized and/or shaped so that the ribs do not have difficulty moving between turns of the helically wound strakes as the cleaning device is moved along a length of the tubular structure. The ribs should not be so large either in the lateral or vertical directions that they have a difficult time moving along or between the helical strakes. If desired, in one or more embodiments, the ribs may optionally be angled helically with an angle approximately corresponding to the angle of the helical strakes. As yet another option, the radial height of the ribs may be short enough to be far enough away from the tubular structure and the strakes that they would not contact. Alternatively, the ribs may be designed to contact the strakes to aid in cleaning the strakes and/or facilitate the rotation of the drum about the tubular structure.

Ribs 352A, 352B1/352B2, and 352C may either be made of the same material as the drum or of a different material. The ribs may be formed integrally with the drum or they may be attached to the inner surface of the drum. The ribs are optional and not required.

Referring again to FIG. 3, the cleaning device may have a latch, a lock, a magnetic latch, a clasp, a pin utilizing deformation, a pin in a hole, or other closure maintaining mechanism 354. The latch or other mechanism may help to temporarily keep the cleaning device closed around the tubular structure. Alternatively, or in addition, the latch or other mechanism may optionally be included on one or more arms. As yet another option, pressure applied to the arms or the sections of the drum from, for example, an ROV, may be used to help keep the device closed.

FIG. 4:

Other ways of rotationally coupling the drum with one or more pairs of arms, in addition to the way shown in FIG. 2, are also contemplated. FIG. 4 is a cross-sectional front view illustrating an embodiment of cleaning device 410 around tubular structure 402. Cleaning device 410 has a single central pair of arms 412 and drum 430. The single central pair of arms may be located generally toward the longitudinal center of the drum.

The pair of arms has left arm or section 416 and right arm or section 418 pivotally connected by arm hinge or pivot joint 426. The drum has left section 432 and right section 434 pivotally connected by drum hinge or pivot joint 436.

The left arm has fiducial or alignment mark or structure 438 and the drum has corresponding fiducial or alignment mark or structure 439. Mark or structure 438 of the arm and mark or structure 439 of the drum is vertically aligned when drum hinge 436 is vertically aligned with arm hinge 426. When such alignment is achieved, the pair of arm and the drum may be opened together.

In one embodiment, drum 430 has a male ridge structure 439, and arm 412 has a female groove structure 438. In operation, when the drum 430 and arm 412 are aligned, male ridge structure 439 may be inserted into female groove structure 438 to lock their relative movement, and allow the hinges 426 and 436 to be aligned so that drum and arms can be opened. In order to allow relative rotational movement of drum 430 and arm 412, male ridge structure 439 may be removed from female groove structure 438, for example male ridge structure 439 may be a removable pin or a ridge that is moveable in the radial direction to engage with female groove structure 438 and then be retracted.

In another embodiment, drum 430 and arm 412 have a female groove structure 438, 439. In operation, when the drum 430 and arm 412 are aligned, a pin or other structure (not shown) may be inserted into female groove structures 438, 439 to lock their relative movement, and allow the hinges 426 and 436 to be aligned so that drum and arms can be opened. In order to allow relative rotational movement of drum 430 and arm 412, the pin or other structure may be removed from female groove structures 438, 439.

Refer now to the rotational connection used to rotationally connect the drum with the pair of arms. The rotational connection includes a pair of interlocked annular or ring-shaped lips.

Drum 430 has first annular or ring-shaped lip 440 of the pair. First annular or ring-shaped lip 440 of the drum may project radially outward as a rim, rib, or other annular or ring-shaped lip from the circumference or perimeter near the center of the drum. First annular or ring-shaped lip 440 may have T-shaped structure 446.

Central pair of arms 412 together forms second annular or ring-shaped lip 442 of the pair. Second annular or ring-shaped lip 442 may project radially outward, upward, radially outward again, downward, radially inward, and then slightly upward again. In other words, the second annular or ring-shaped lip may form a C-shaped structure. Second annular or ring-shaped lip 442 provides an annular or ring-shaped groove 444 around the perimeter of the drum.

The groove in the C-shaped structure of second annular or ring-shaped lip 442 represents female opening or structure 444. T-shaped structure 446 of first annular or ring-shaped lip 440 represents a male member or structure. The male member or structure may be inserted into the female member or structure.

This connection, which is illustrative and not limiting, may allow the drum to rotate relative to the central pair of arms. In alternate embodiments, a portion of the annular or ring shape of either of the lips may optionally be omitted, as long as there is some part to hold the drum in place when the arms and drum are open so that the drum does not fall out. For example, each of the arms may have such a lip on only about half their perimeter. Other ways of rotationally connecting drums and one or more arms are also contemplated and will be apparent to those skilled in the art.

FIG. 5:

FIG. 5 is a front view illustrating an embodiment of cleaning device 510 including a drum 530 optionally having a plurality of drum hinges or other pivot joints 536A, 536B. The cleaning device has a single central pair of arms 512 and drum 530. The pair of arms has arm hinge or other pivot joint 526, and/or pair of arms may have a plurality of hinges or other pivot joints that may be aligned with drum pivot joints 536A, 536B.

In one or more embodiments, the drum optionally has more than two sections.

In the front view, three sections 532, 533, and 534 are visible, although it is to be appreciated that the drum may have one or more additional sections that are not visible from the front. The three sections include as viewed, leftmost section 532, central section 533, and rightmost section 534.

In one or more embodiments, the drum optionally has a plurality of drum hinges or other pivot joints 536A, 536B. A leftmost drum hinge or other pivot joint 536A connects leftmost section 532 and central section 533 together. Rightmost drum hinge or other pivot joint 536B connects central section 532 and rightmost section 534 together.

When leftmost drum hinge 536A is vertically aligned with arm hinge 526, the leftmost drum hinge may allow the leftmost drum section 532 and the central drum section 533 to swing, pivot, or move between an open position and a closed position.

Likewise, when rightmost drum hinge 536B is vertically aligned with arm hinge 526, the rightmost drum hinge may allow the central drum section 532 and the rightmost drum section 533 to swing, pivot, or move between an open position and a closed position.

When the drum rotates, for example in conjunction with cleaning the tubular structure, drum hinges 536A, 536B may become unaligned with the arm hinge 526. It may be difficult to open cleaning device when one of the drum hinges is not sufficiently aligned with the arm hinge. Accordingly, the drum may be rotated until one of the drum hinges sufficiently aligns with the arm hinge. In one aspect, the cleaning device or an ROV that uses the cleaning device may have an arm or other mechanism to rotate the drum.

One potential advantage of including more than two drum sections and a plurality of drum hinges is that it increases the likelihood that at least one of the drum hinges is close to the arm hinge. For example, in the illustration, even though leftmost drum hinge 536A is separated from the arm hinge by a greater distance d1, rightmost drum hinge 536B is only separated from the arm hinge by a lesser distance d2. In this way, the drum need not be rotated as much before a closest drum hinge comes into alignment with the arm hinge, which may help to save time needed to open cleaning device.

In one or more embodiments, drum hinges or other pivot joints may be approximately equally spaced apart around a circumference or perimeter of the drum. For example, two drum hinges may be diagonally spaced apart on opposite sides of the drum, for example about 180 degrees apart; three drum hinges may be spaced apart about 120 degrees from each other, etc.

As before, fiducial or alignment marks or structures (not shown) may be used to facilitate alignment. In one or more embodiments, a separate corresponding fiducial or alignment mark or structure may be included for each separate drum hinge.

FIG. 6:

FIG. 6 is a partial top view of an embodiment of cleaning device 610 having hydraulic arms 648, 650 and hydraulic system 652 to open and close the cleaning device. (The top view is as if looking down on upper pair of arms 212 of cleaning device 210 of FIG. 2.) Upper left arm or section 616, upper right arm or section 618, left section of drum 632, right section of drum 634, drum hinge 636, arm hinge 624, and tubular structure 602 are shown.

Hydraulic arm 648 is connected to upper left arm or section 616. Hydraulic arm 650 is connected to upper right arm or section 618. A hydraulic system may hydraulically actuate the hydraulic arms to open (in the direction of arrows) and thereby open arms 616, 618.

In one or more embodiments, cleaning device 610 may also optionally have a frame-like structure, truss-like structure, or other structure that may be used as a handle or grip 654. The structure may be connected to the arms and/or may support the hydraulic system. An ROV or diver may use such a handle or grip to hold and/or maneuver the cleaning device.

Suitable tools that could be used to operate cleaning device are disclosed in U.S. patent application Ser. No. 10/784,536, having attorney docket number

TH1853.04; U.S. patent application Ser. No. 10/848,547, having attorney docket number TH2463; U.S. patent application Ser. No. 11/596,437, having attorney docket number TH2900; U.S. patent application Ser. No. 11/468,690, having attorney docket number TH2926; U.S. patent application Ser. No. 11/612,203, having attorney docket number TH2875; U.S. Patent Application No. 60/806,882, having attorney docket number TH2879; U.S. Patent Application No. 60/826,553, having attorney docket number TH2842; U.S. Pat. No. 6,695,539; U.S. Pat. No. 6,928,709; and U.S. Pat. No. 6,994,492; which are herein incorporated by reference in their entirety.

Suitable sleeves, suitable collars, and suitable devices to install exterior to structures such as fairings and strakes, and methods of their installation are disclosed in U.S. patent application Ser. No. 10/839,781, having attorney docket number TH1433; U.S. patent application Ser. No. 11/400,365, having attorney docket number TH0541; U.S. patent application Ser. No. 11/419,964, having attorney docket number TH2508; U.S. patent application Ser. No. 11/420,838, having attorney docket number TH2876; U.S. Patent Application No. 60/781,846 having attorney docket number TH2969; U.S. Patent Application No. 60/805,136, having attorney docket number TH1500; U.S. Patent Application No. 60/866,968, having attorney docket number TH3112; U.S. Patent Application No. 60/866,972, having attorney docket number TH3190; U.S. Pat. No. 5,410,979; U.S. Pat. No. 5,410,979; U.S. Pat. No. 5,421,413; U.S. Pat. No. 6,179,524; U.S. Pat. No. 6,223,672; U.S. Pat. No. 6,561,734; U.S. Pat. No. 6,565,287; U.S. Pat. No. 6,571,878; U.S. Pat. No. 6,685,394; U.S. Pat. No. 6,702,026; U.S. Pat. No. 7,017,666; and U.S. Pat. No. 7,070,361, which are herein incorporated by reference in their entirety.

FIG. 7:

FIG. 7 illustrates an embodiment of remotely operated vehicle (ROV) 760 manipulating a cleaning device 710 in sub sea system 700. Alternatively, a diver instead of the ROV may manipulate the cleaning device.

Surface structure 701 is connected to subsurface structure 704 adjacent to seafloor 705 by tubular structure 702. In one or more embodiments, the tubular structure may have helical strakes 708, or other structures or devices that twist, wind, or spire around at least a potion of the length of the tubular structure.

In one or more embodiments, the cleaning device may be connected to the surface structure through one or more umbilicals or lines 762 extending from the surface structure. In one or more embodiments, one or more umbilicals or lines may extend from the surface structure to the cleaning device for the purpose of operating various components of the cleaning device.

In one or more embodiments, the cleaning device may be a least partially or fully physically supported or suspended by a support line or winch 762 that may be used to lower and/or raise the cleaning device within the water. By way of example, the support line or winch may be wound around a spring-mounted spool (not shown) attached to the surface structure to control slack in the support line when the cleaning device is moved up and down along the structure being cleaned.

In various embodiments, power umbilicals or lines, control umbilicals or lines, high pressure water umbilicals or lines, or any combination thereof, may be included in line 762. For example, a power umbilical or line may be used to provide power to the cleaning device, for example to rotate brushes, pumps, etc. As another example, a control umbilical or line may be used to provide control signals to the cleaning device, for example to turn brushes on or off or open or close arms. As yet another example, a water or other fluid supply line may be used to supply pressurized water or fluid to cleaning device to assist with cleaning or to sweep freed debris away from the cleaning device.

Alternatively, control, power, or water, or any combination thereof, may be provided locally. For example, a ROV or diver may provide control to the cleaning device locally. A battery, fuel cell, hydraulic pump, or other power source may provide power to the cleaning device locally. A high pressure water pump, receiving power from a local power source or from a power line from surface structure, may provide high pressure water to the cleaning device locally.

ROV 760 may represent any one of various different types of ROVs known in the arts. Commonly the ROV may have one or more propellers or other propulsion devices. The ROV may also have sensors, cameras, or other guidance devices. The ROV may also optionally have communication systems and control systems to allow its movement and operation to be controlled from a remote location, such as surface structure 701, for example with the use of an umbilical to structure 701 or a ROV control vessel (not shown).

The ROV may have one or more arms 764, 766. The arms may be used to grasp, clamp, or otherwise hold the cleaning device, and allow the ROV to manipulate the cleaning device. As shown, the ROV may have a first arm 764 to hold a first arm 712 of the cleaning device, and the ROV may have a second arm 766 to hold a second arm 714 of the cleaning device. Alternatively, if desired, the ROV may be permanently or at least fixedly connected to the cleaning device.

The ROV may move the cleaning device into proper position relative to the tubular structure and the helical strakes. Once in proper position relative to the tubular structure, the ROV may use one or more arms to open the cleaning device, move the cleaning device until it encompasses the tubular structure, and close the cleaning device around the tubular structure. Then the ROV, the support line, or both, may assist with moving the cleaning device up and/or down along a length of the tubular structure as shown by arrow 768. Drum may rotate around tubular structure as shown by arrow 770.

Once the strakes and/or the tubular structure have been sufficiently cleaned, the ROV may use one or more arms to open the cleaning device, and remove the cleaning device from the tubular structure by pulling or drawing the cleaning device away from the tubular structure. Such a process may be repeated on another strake and/or tubular structure, or on a different portion of the same tubular structure.

The cleaning devices described herein, and the arms and drums and other various parts thereof, may be made of plastic, metal, or a combination thereof. Examples of suitable plastics include, but are not limited to, polyalkenes (e.g., polyethylene, polypropylene, etc.), polyvinyl chloride (PVC), and acrylonitrile butadiene styrene (ABS), fiberglass, other fiber reinforced plastics, other plastics used in similar marine environments, and the like, and combinations thereof, to name just a few examples. Examples of suitable metals include, but are not limited to, steel, stainless steel, aluminum, coated metals, other metals used in similar marine environments, and the like, and combinations thereof. The cleaning devices or components may be molded, welded, bent, cast, glued, assembled, fastened, or otherwise formed with manufacturing techniques as are known in the art.

ILLUSTRATIVE EMBODIMENTS

In one embodiment, there is disclosed a tool for cleaning subsea structures, the tool comprising a frame comprising a stationary frame portion; and a rotating frame portion rotationally connected to the stationary frame portion; and at least one cleaning device attached to the rotating frame portion. In some embodiments, the tool comprises a clamshell device comprising at least one set of clamps. In some embodiments, the tool also includes a connection to a remote location, the remote location comprising a power source. In some embodiments, the frame has a height from 0.5 to 5 meters. In some embodiments, the subsea structures are selected from the group consisting of bare tubulars, vortex-induced vibration reduction devices and drag reduction devices, such as helical strakes. In some embodiments, the tool also includes a hydraulic, pnematic, or electric system supported by the frame adapted to open and/or close the frame around the subsea structures. In some embodiments, the cleaning device is selected from brushes, scrapers, water jets, ultrasonic and/or cavition devices. In some embodiments, the rotating frame portion comprises a plurality of sections adapted to surround from 180 degrees to 360 degress of a circumference of the subsea structure. In some embodiments, the tool also includes at least one connector between two adjacent sections, the connector adapted to secure the adjacent sections, wherein the sections may be secured manually, remotely, or autonomously.

In one embodiment, there is disclosed a method of remotely cleaning a subsea structure, the method comprising positioning a tool adjacent to the subsea structure, wherein the tool comprises a stationary portion and a rotating portion comprising at least one cleaning device; moving the tool to position the tool around the subsea structure; closing the tool to a closed configuration to close the tool around the subsea structure, wherein the tool covers from about 10% to about 100% of a circumference of the subsea structure; holding the stationary portion and moving the stationary portion along a length of the subsea structure, rotating the rotating portion rotates about the circumference of the subsea structure; and cleaning at least a portion of the subsea structure. In some embodiments, the tool is operated underwater with a remotely operated vehicle, wherein the remotely operated vehicle is connected to the stationary portion. In some embodiments, the tool is closed around the structure above a water level, and is activated to clean the structure below the water level. In some embodiments, the cleaning comprises at least one of the group consisting of brushing, scraping, spraying, and vibrating the structure.

In the description above, for the purposes of explanation, numerous specific details have been set forth in order to provide a thorough understanding of the embodiments of the invention. It will be apparent however, to one skilled in the art, that one or more other embodiments may be practiced without some of these specific details. The particular embodiments described are not provided to limit the invention but to illustrate it. The scope of the invention is not to be determined by the specific examples provided above but only by the claims below. In other instances, well-known circuits, structures, devices, and operations have been shown in block diagram form or without detail in order to avoid obscuring the understanding of the description.

It will also be appreciated, by one skilled in the art, that modifications may be made to the embodiments disclosed herein, such as, for example, to the sizes, shapes, configurations, forms, functions, materials, and manner of operation, and assembly and use, of the components of the embodiments. All equivalent relationships to those illustrated in the drawings and described in the specification are encompassed within embodiments of the invention.

It should also be appreciated that reference throughout this specification to “one embodiment”, “an embodiment”, or “one or more embodiments”, for example, means that a particular feature may be included in the practice of the invention. Similarly, it should be appreciated that in the description various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects may lie in less than all features of a single disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of the invention. 

1. A tool for cleaning subsea structures, the tool comprising: a frame comprising: a stationary frame portion; and a rotating frame portion rotationally connected to the stationary frame portion; and at least one cleaning device attached to the rotating frame portion.
 2. The tool of claim 1, wherein the tool comprises a clamshell device comprising at least one set of clamps.
 3. The tool of claim 1, further comprising a connection to a remote location, the remote location comprising a power source.
 4. The tool of claim 1, wherein the frame has a height from 0.5 to 5 meters.
 5. The tool of claim 1, wherein the subsea structures are selected from the group consisting of bare tubulars, vortex-induced vibration reduction devices and drag reduction devices, such as helical strakes.
 6. The tool of claim 1, further comprising a hydraulic, pnematic, or electric system supported by the frame adapted to open and/or close the frame around the subsea structures.
 7. The tool of claim 1, wherein the cleaning device is selected from brushes, scrapers, water jets, ultrasonic and/or cavition devices.
 8. The tool of claim 1, wherein the rotating frame portion comprises a plurality of sections adapted to surround from 180 degrees to 360 degress of a circumference of the subsea structure.
 9. The tool of claim 8, further comprising at least one connector between two adjacent sections, the connector adapted to secure the adjacent sections, wherein the sections may be secured manually, remotely, or autonomously.
 10. A method of remotely cleaning a subsea structure, the method comprising: (a) positioning a tool adjacent to the subsea structure, wherein the tool comprises a stationary portion and a rotating portion comprising at least one cleaning device; (b) moving the tool to position the tool around the subsea structure; (c) closing the tool to a closed configuration to close the tool around the subsea structure, wherein the tool covers from about 10% to about 100% of a circumference of the subsea structure; (d) holding the stationary portion and moving the stationary portion along a length of the subsea structure, (e) rotating the rotating portion rotates about the circumference of the subsea structure; and (f) cleaning at least a portion of the subsea structure.
 11. The method of claim 10, wherein the tool is operated underwater with a remotely operated vehicle, wherein the remotely operated vehicle is connected to the stationary portion.
 12. The method of claim 10, wherein the tool is closed around the structure above a water level, and is activated to clean the structure below the water level.
 13. The method of claim 10, wherein the cleaning comprises at least one of the group consisting of brushing, scraping, spraying, and vibrating the structure. 